There are many different causes for
wrist pain so in our differential,
we have to think of a potential
mechanical causes of wrist pain
Fractures could be a potential mechanical
cause, avascular necrosis, ligamentous tears,
DeQuervain's tenosynovitis, potential neoplasms
or ganglions and somatic dysfunctions
are all possible mechanical
causes of wrist pain.
Keinbock's disease is due to decreased blood
flow to some of the bones in the wrist
and then so that could develop into
avascular necrosis of the lunate bone,
you could have irritation and
inflammation of your tendons
and specifically if you have inflammation of the
extensor pollicis brevis and ABductor pollicis longus,
these tendons extend the thumb and
so overuse injuries of the thumb
could potentially contribute to DeQuervain's
tenosynovitis is when you have pain
along your thumb and in
your metacarpal joints
and so overuse sometimes could lead
to DeQuervain's tenosynovitis.
There could be ligamentous injuries
in the wrist usually due to trauma
and so one of the relationships
that you want to take a look at
is between the scaphoid
and lunate bone,
sometimes on x-ray you'll see
increased space between those bones
leading to increase your suspicion
for possible ligamentous injuries.
Patients with scapholunate ruptures tend to
have more of a radial deviation of wrist pain
whereas patients with lunotriquetral rupture of the
ligaments tend to have more ulnar deviations of the wrist
and increased wrist pain.
There are different orthopedic test that we could
perform to help narrow down our differential,
especially for suspicious of a specific injury
and so if we are suspicious of a potential
ligamentous injury between a scaphoid and
lunate bone, we could perform a Watson's test.
What the Watson's test does is to check for the
stability between the scaphoid and lunate bone,
what we wanna do is to hold
on to the scaphoid bone,
and then we're going to start with the
pateint's wrist in ulnar deviation
and while holding pressure on that scaphoid, we're gonna
have the patient try to radially deviate the hand.
As the patient moves her hand through the radial
deviation, if the patient have any increased pain,
then that would be a positive test or a
positive Watson's test which indicates
possible ligamentous injury between
the lunate and scaphoid bone.
This is important to perform because if
you have a missed scaphoid fracture,
sometimes that could lead to avascular necrosis
of the bone and there is severe injury.
Shuck's test is a special test we could
perform to check fo perilunate instability.
So that lunate bone in the center of the
wrist sometimes is suspect to injury
and so if we wanna check whether or not the
ligaments around that lunate bone has been injured,
we could perform the Shuck test.
To perform the Shuck's test, what we do is
we start with the patient's hand in flexion
and while holding the patient's hand in
flexion, we're gonna ask the patient to try to
extend their wrist and as they extend their wrist, if
there's pain in that area around the llunate bone,
then that is a positive test indicating
possible perilunate instability.
Finklestein's test is a test that we could
do to check for DeQuervain's tenosynovitis
and so remember DeQuervain's tenosynovitis
is inflammation by the thumb
so if the patient has a lot of pain by the
thumb and the radial aspect of the wrist,
we could perform this test.
The test is performed by asking the patient
to hold their fingers around the thumb
and then ulnar
deviate their wrist.
This puts a stretch into those
tendons and if there's inflammation,
then there'll be acute pain there, so a positive
test would be pain on the lateral wrist
as the ulnar deviate, their fist with
their thumb enclose within their fingers,
so again a positive test indicates
possible DeQuervain's tenosynovitis.
There are different neurologic
causes of wrist pain.
we need to consider possible distal
posterior interosseous nerve syndrome,
carpal tunnel syndrome,
injury to the radial nerve,
injury to the ulnar nerve at the the tunnel of
Guyon, or also thoracic outlet syndrome
Carpal tunnel syndrome is due
to compression of median nerve.
The median nerve runs through
this carpal tunnel at the wrist.
The carpal tunnel's composed of the wrist bones,
and also the flexor retinaculum on top of it.
Within this tunnel in the space runs our
finger flexors and the median nerve
and due to swelling or any
sort of injury in this area,
it could compress on that nerve and
cause symptoms of decreased sensation
and also atrophy of the thenar muscles and so what
we could do is to perform different special test.
If we're suspicious of patients with numbness and tingling,
usually more pain at night, decreased grip strength,
we could perform two different tests to
try to confirm carpal tunnel syndrome
and so we have Tinel's
test and Phalen's test.
Tinel's test is a test that we could perform
along any nerve at different regions.
Tinel's sign itself for the median nerve is to check
for the irritation of the median nerve
as it passes through
the carpal tunnel.
So here what we want to do is to
tap along the carpal ligament
along where the median nerve would run
and just that tapping over that region,
could reproduce that numbness and tingling and
paresthesia over the median nerve distribution,
that would be a positive test
for carpal tunnel syndrome.
Phalen's test is another test that we could
perform to check for carpal tunnel syndrome.
Here, we're gonna ask our patients
to hold their wrist in flexion
with the back of the hands
together up for one minute,
patients usually will complain of any sort of numbness and
tingling and pain along that median nerve distribution
that would indicate a positive test, and what you're
doing here is because you're compressing
along the wrist here that's
gonna recreate the pain,
An alternative to Phalen's
test is a Prayer's test,
and here you're gonna actually tell the patient to put the
palms together kind of like holding your hands in prayer
and that extension of the wrist
is gonna irritate the nerve
and again, numbness and tingling
and pain would be a positive test.
Ulnar nerve compression.
So the ulnar nerve when it's compressed, will
lead to increased flexion in the fingers
and so because the ulnar nerve
innervates the extensor tendons,
the fingers will then be stuck more in flexion
or give you this kind of claw hand deformity
The ulnar nerve could be potentiallly
compressed at Guyon's canal.
So Guyon's canal is where the
pisiform and the hamate meet
and along there is a small canal
where the nerve passes through
and innervates the pinky and the
ulnar half of the forefinger,
and so patients with numbness and tingling
of the pinky and decreased grip strength
especially of those fingers, you have your
increased suspicion of ulnar nerve compression.
The ulnar nerve can also be
compressed at the elbow.
So cubital tunnel syndrome occurs
when the ulnar nerve is compressed
as it passes by the medial
epicondyle of the elbow.
And so this is similar to when you
hit your elbow and they call it,
"hitting the funny bone" and you get that
shooting, radiating paresthesia into your fingers
again more by the ulnar half of
the forefinger and your fifth digit
and so the ulnar nerve could be
compressed at the cubital tunnel
and patients could also have
some decrease in grip strength.
Radial nerve damage,
The radial nerve does not run through tight
spaces like the ulnar and median nerve does
so it does not tend to be entrapped like those
two nerves, but the radial nerve can get injured
due to acute trauma, injury, fractures
and so if we injure the radial nerve,
patients will have the inability to really
extend the digits and also the wrist,
you could also have a loss of sensation
on the radial side of the hand
The radial nerve divides and there's a posterior
interosseous nerve that drops deeper by the elbow,
and sometimes the posterior
interosseous nerve could be entrapped
and that will lead to weaknes
of the wrist on extension
but because it dos not do sensation to
the hand, the sensation will be intact
So if you have someone that has difficulty
with extending the wrist and fingers,
you have to suspect more of a posterior interosseous
nerve entrapment especially if sensation is intact,
There are many different systemic causes
of wrist pain that we have to consider,
patients with different metabilic conditions such as diabetes
and hypothyroidism could have issues with the wrist and hand,
patients with osteomyelitis, patients with rheumatologic
disorders frequently present with wrist and hand complaints
especially osteoarthritis, so with osteoarthritis, with
wear and tear, there might be more pain with overuse,
you might see more of the joints
at the metacarpal joints,
more inflamed and irritated with
rheumatologic like rheumatoid arthritis,
you'll see some nodules that occur along the
fingers, sometimes, a lot of wrist pain,
sometimes more deviations
of the wrist and fingers.
Reflex sympathetic dystrophy usually secondary
to some sort of trauma to the extremities
and then patients will have uncontrolled pain, pain
to just light touch, maybe dysautonomia to the hand,
so there are lot of different things
that could occur post trauma,
usually after surgery or some sort of traumatic
injury to cause reflex sympathetic dystrophy.
Peripheral neuropathy is also another potential systemic
cause of wrist and hand pain that we need to consider.
Allen's test is a special test that we could perform to
determine whether or not the blood flow to the hand,
through the radial and ulnar
artery is patent and intact,
and so what we want to do with
this test is to have the patient
open and close your fist while we occlude the
arteries and then release one at a time,
and then when you release it, by occluding it
have the patient pump their hand open and close
the hands become more pale and then what you
do is when you release one artery at a time,
you should see that the hand starts to return
circulation and become more pink and flushed,
and so, you'd want to do that one side at a time, release
one artery at a time to make sure it's patent on both sides
and this is important to perform prior
to any sort of arterial blood draws
to make sure that there's
proper flow from both sides
and that you're not going to cause a
clot or occlude circulation to the hand.
And so by understanding the anatomy and physiology of the
hand and how to apply these different special tests,
it could help us with better evaluating our
patients with wrist and hand complaints and pain.